1. Field of the Invention
The present invention relates to an escalator, and in particular to an improved step combining system for an escalator, capable of easily attaching/detaching a step to/from a connecting shaft connected to a step chain.
2. Description of Conventional Art
Generally, a conventional elevator, as shown in FIG. 1, mainly includes a step unit 20 for transferring passengers, a handrail unit 10, provided at both sides of the step unit 20, for rotatively moving along a predetermined track, and an upper mechanical unit 30 for driving the handrail unit 30 and step unit 20.
As shown in FIG. 2, the step unit 20 is provided with steps 21 for transferring passengers, a step rear roller 22 formed at both ends below one side of the step 21 as a single body, a connecting shaft 23 having first joints 23a provided at each end thereof as a single body, and a pair of step front rollers 25 formed at both ends of the connecting shaft 23 and connected with each step chain 24. In addition, second joints 21a are formed at each end under the other side of step 21 as a single body, and bolt 26 and nut 27 are provided at each end of the connecting shaft 23 to connect the second joints 21a with the first joints 23a.
As shown in FIGS. 1 and 3, the upper mechanical unit 30 includes a motor 31 providing driving force, a speed reducer 32, directly connected with the motor 31, for reducing the rotary speed of the motor 31, thus increasing torque, a driving sprocket 34 connected with a rotary shaft of the speed reducer 32, and a driving shaft 37 which a driving sprocket 34', connected with the driving sprocket 34 by a driving chain 33, is provided at one side thereof and which a driving terminal gear 35 is provided at both sides thereof.
With reference to FIG. 3, the operation of the thusly constructed conventional escalator will be described.
The driving force of the motor 31 of the mechanical unit 30 is reduced by the speed reducer 32, down to a certain speed, and is conveyed to the driving sprocket 34 connected with the speed reducer 32.
Rotary power of the driving sprocket 34 is conveyed to the driving sprocket 34' by the driving chain 33, thus causing the driving sprocket 34' to rotate the driving shaft 37.
When the driving shaft 37 rotates, a step 21, which is connected with the driving terminal gears 35 provided at each end of the driving shaft 37 by the step chain 24, rotates upward and downward along guide rails (not shown).
In the conventional escalator, a step combining system of the step unit 20 as shown in FIG. 2 is provided with the bolt 26 and nut 27, which combine the second joints 21a of the step 21 with the first joints 23a of the connecting shaft 23 connected with the step chain 24.
However, when separating the connecting shaft 23 connected with the step chain 24 from the step 21, step 21 must be moved to the upper mechanical unit 30, unfastening the bolts 26 from the step 21, moving the step 21, from which the bolt 26 is unfastened, to a side panel (a), opening the side panel (a), and taking out the step 21.
The above-described actions result from which the first joints 21a formed in the step 21 protrude in a forward direction of the step 21, and the protruding upper portions of the first joints 21a are covered by another step, whereby the bolts 26 fastening the step 21 and the connecting shaft 23 can not be readily unfastened from an exterior above the step 21.
Accordingly, in the conventional step combining system, the separating operation of the step is complicated, timeconsuming, and not effectively achieved.